For the element in a news broadcast storyboard that briefly states what the story is about and, crucially, why it would make an interesting story. This implies an element that not only summarizes th

The question asks for the element in a news broadcast storyboard that briefly states what the story is about and, crucially, why it would make an interesting story. This implies an element that not only summarizes the content but also explains its significance or appeal.

• A. Lead: The lead (or lede) is the opening sentence or paragraph of a news story. Its primary function is to summarize the most important facts (who, what, when, where, why, how) to immediately inform the audience. While it states what the story is about, it doesn't always explicitly explain why it's interesting in a persuasive manner; it focuses on the core facts.
• B. Nut graph: The "nut graph" (short for "nutshell paragraph") is a paragraph, typically following the lead, that explains the central point or theme of the story. It tells the audience why the story is important, relevant, or interesting, providing context and answering the "so what?" question. This perfectly matches the description in the question.
• C. Background: Background information provides context, history, or additional details necessary to understand the story fully. It supports the main narrative but doesn't primarily serve to briefly state what the story is about and why it's interesting.
• D. Backup for the lead: This is not a standard journalistic term for a specific structural element that fulfills the described function. While a lead needs supporting information, "backup for the lead" doesn't precisely define an element that explains the story's appeal.

The "nut graph" is specifically designed to explain the significance and relevance of a news story, thereby stating why it would make an interesting story, in addition to summarizing its core content.

The correct option is B.
$\boxed{\text{B. Nut graph}}$